$ps -e "kworker$" error: unknown sort specifier Usage: ps [options] Try 'ps --help ' or 'ps --help' for additional help text. For more details see ps(1). $ps -ef | grep "^daemon" daemon 639 1 0 May04 ? 00:00:00 /usr/sbin/atd -f $ps -ef | grep "^rtkit" rtkit 1245 1 0 May04 ? 00:00:00 /usr/lib/rtkit/rtkit-daemon $ps -ef | grep "^systemd+" systemd+ 522 1 0 May04 ? 00:00:00 /lib/systemd/systemd-timesyncd $